The present invention provides a liquid crystal display capable of making the variations and the oblique lines, which are caused on the screen in the liquid crystal display using the TN liquid crystal panel, less visible. The liquid crystal display includes a video signal reception section adapted to receive a video signal, a signal input detection section adapted to detect presence or absence of the video signal, a luminance control section adapted to control the luminance of the backlight, and a control section adapted to instruct the luminance control section to reduce the luminance of the backlight as a predetermined amount in the case in which the signal input detection section fails to detect the video signal.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A liquid crystal display, comprising: a Twisted Nematic (TN) liquid crystal panel and a backlight for emitting light from behind the liquid crystal panel, and varying transmission of each pixel in the liquid crystal panel based on a video signal, thereby displaying an image with the transmitted light that is transmitted through each pixel of the liquid crystal panel; a video signal reception section for receiving the video signal contained in a Transport Stream of digital television broadcasting signal; a signal input detection section for detecting the video signal based on a table which records channel numbers contained in the Transport stream; a luminance control section for controlling the luminance of the backlight with Pulse Width Modulation (PWM) control for varying a duty ratio of a pulse signal; a control section for outputting a control signal to the luminance control section so that the luminance control section varies the duty ratio of the pulse signal; a table for storing a luminance control range that has a range of value which can be set by an operation input; wherein when the video signal is detected by the signal input detection section, the control section outputs the control signal so that the luminance control section controls the luminance of the backlight based on the luminance control range and when the video signal is not detected by the signal input detection section, the control section outputs the control signal so that the luminance control section reduces the value of the luminance of the backlight lower than the minimum value of the luminance control range.
2. The liquid crystal display according to claim 1 , further comprising: a solid color screen display section for making the liquid crystal panel to display a solid color image when the video signal is not detected by the signal input detection section.
3. The liquid crystal display according to claim 1 , wherein the control section instructs the luminance control section to increase the luminance of the backlight in a phased manner in the case in which the signal input detection section detects the video signal after the control section makes the luminance control section perform luminance control for reducing the luminance of the backlight.
4. The liquid crystal display according to claim 1 , wherein the video signal reception section has a plurality of input units for receiving the video signal of a different kind of system, and the signal input detection section switches detection methods of the video signal in accordance with the input units for the selected video signal.
5. The liquid crystal display according to claim 1 , wherein, if the signal input detection section can not detect a channel number corresponding to selected channel in the table the signal input detection section determines the video signal is not detected.
6. The liquid crystal display according to claim 1 , wherein the Transport Stream includes in a Identifier for identifying the place of the received digital television broadcasting where the video signal of each channel is stored, if the signal input detection section can not detect the Identifier corresponding to selected channel for predetermined time the signal input detection section determines the video signal is not detected.
7. A liquid crystal display, comprising: a Twisted Nematic (TN) liquid crystal panel and a backlight for emitting light from behind the liquid crystal panel, and varying transmission of each pixel in the liquid crystal panel based on a video signal, thereby displaying an image with the transmitted light that is transmitted through each pixel of the liquid crystal panel; a video signal reception section for receiving the video signal transmitted with a HDMI transmission channels; a signal input detection section for detecting the video signal based on a clock signal transmitted with the HDMI transmission channels and a sync signal in one frame of the video signal; a luminance control section for controlling the luminance of the backlight with Pulse Width Modulation (PWM) control for varying a duty ratio of a pulse signal; a control section for outputting a control signal to the luminance control section so that the luminance control section varies the duty ratio of the pulse signal; a table for storing a luminance control range that has a range of value which can be set by the operation input; wherein when the video signal is detected by the signal input detection section, the control section outputs the control signal so that the luminance control section controls the luminance of the backlight based on the luminance control range and when the video signal is not detected by the signal input detection section, the control section outputs the control signal so that the luminance control section reduces the value of the luminance of the backlight lower than the minimum value of the luminance control range.
8. A liquid crystal display, comprising: a Twisted Nematic (TN) liquid crystal panel and a backlight for emitting light from behind the liquid crystal panel, and varying transmission of each pixel in the liquid crystal panel based on a video signal, thereby displaying an image with the transmitted light that is transmitted through each pixel of the liquid crystal panel; a video signal reception section for receiving the video signal inputted through an S terminal; a signal input detection section for detecting the video signal based on a sync signal in one frame of the video signal; a luminance control section for controlling the luminance of the backlight with Pulse Width Modulation (PWM) control for varying a duty ratio of a pulse signal; a control section for outputting a control signal to the luminance control section so that the luminance control section varies the duty ratio of the pulse signal; a table for storing a luminance control range that has a range of value which can be set by the operation input; wherein when the video signal is detected by the signal input detection section, the control section outputs the control signal so that the luminance control section controls the luminance of the backlight based on the luminance control range and when the video signal is not detected by the signal input detection section, the control section outputs the control signal so that the luminance control section reduces the value of the luminance of the backlight lower than the minimum value of the luminance control range.
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
October 21, 2008
September 2, 2014
Browse 5M+ US patents with plain-English claim translations and AI-generated analysis.